Damping valve device for a vibration damper

Abstract

Damping valve device for a vibration damper, comprising a throttle point in connection with a valve element and a flow guide surface, wherein the valve element can be transferred from a passage position into a throttle position depending on the flow velocity of a damping medium within the throttle point, wherein the valve element is arranged as a ring element with a variable diameter within an annular groove of a valve carrier, wherein the damping force characteristic of the damping valve device is actively adjustable by supplying external energy, wherein the damping medium displaced by the throttle point is designed as a rheological medium and the flow guide surface is designed as a force field generating element for a viscosity change of the damping medium.

Description

[0001] The invention relates to a damping valve device for a vibration damper according to the preamble of patent claim 1.

[0002] DE 10 2016 210 790 A1 describes a damping valve device for a vibration damper, comprising a first damping valve that transitions into a through-opening operating position in a first operating range with increasing flow velocity of a damping medium. The first damping valve is formed, for example, by a piston valve or a base valve of the vibration damper. A second operating range with a progressive damping force characteristic of the vibration damper is influenced by a throttle point in conjunction with a valve body that can be transferred from a through-opening position to a throttle position, independent of the stroke position of a piston rod of the vibration damper, depending on the flow velocity within the throttle position, wherein the valve body moves in the closing direction with increasing flow velocity of the damping medium.This creates an additional damping force that eliminates the need for a conventional pull or push stop, which is only effective in one end position of the piston rod.

[0003] The throttle point and the damping valve are hydraulically arranged in series, with the valve body being designed as a ring element with a variable diameter that executes a radial closing movement in the direction of a flow guide surface, where a defined minimum flow cross-section is maintained.

[0004] In DE 10 2019 212 966 A1 it is proposed that the ring element, which can be changed in diameter, is additionally supported by a compressive force within a pressure chamber formed by an annular groove.

[0005] DE 10 2022 204 988 A1 describes a further development of the damping valve device, which in this case is adjustable. The adjustment function is primarily designed for static adjustment, for example, to achieve a specific trigger point of the ring element, which can be adjusted in diameter.

[0006] The object of the present invention is to further develop an adjustable damping valve device with regard to a simple structure and dynamic adjustability.

[0007] In a first variant, the problem is solved by designing the damping medium displaced by the throttle point as a rheological medium and the flow guide surface as a force field generating element for a viscosity change of the damping medium.

[0008] An electrorheological or magnetorheological damping medium offers the possibility of varying the damping force characteristics through the variable viscosity change. This requires no additional moving components within the damping valve device. Simple force field generating elements are sufficient for this function.

[0009] In a preferred embodiment, a cylinder tube of a working cylinder of the vibration damper serves as the force field generating element. As a component within the vibration damper, the cylinder tube is easily accessible for electrical contact.

[0010] The valve element can be designed as the force field generating element. This design directly influences the operating behavior of the damping valve device.

[0011] To ensure a secure power supply to the valve element for the function of the force field generating element, the valve carrier comprises two covers forming the annular groove, both of which are designed as conductive elements for the force field generating element. The valve element, which is subject to play in the annular groove, is thus always connected to the power supply.

[0012] Alternatively or additionally, the valve carrier can be designed as a force field generating element. If the valve carrier and the valve element are provided as force field generating elements, then two throttle points are present in a hydraulic series circuit, with the throttle point formed by the valve element being subject to two adjustment parameters, namely the flow velocity and the field strength.

[0013] To simplify implementation of the invention, the valve carrier is designed in several parts with at least one inserted insulation element. This makes it possible, even with simple means, for the valve element to function outside the field force generator thanks to the insulation, thus making it easy to connect two throttle points in series.

[0014] Another solution is characterized by the fact that the outer surface of the valve element and at least portions of the surfaces forming the annular groove of the valve carrier are designed as force field generating elements. This solution changes the flow situation prevailing in the pressure chamber of the damping valve device.

[0015] To prevent undefined field forces from acting on the valve element, an intermediate ring of the valve carrier, forming the base of the annular groove, is designed as a field generating element. This allows the field lines to run exactly radially and thus in the direction of movement of the valve element.

[0016] In a third solution, the damping valve device has a solenoid coil that exerts a radially acting adjusting force on the valve element. This design also works with conventional damping media.

[0017] The invention will be explained in more detail with reference to the following description of the figures.

[0018] It shows: Fig. 1 Schematic diagram of the vibration damper with damping valve device Fig. 2 Detailed view of Fig. 1 Fig. 3 Alternative to Fig. 2 Fig. 4 Damping valve device with viscosity control in the pressure chamber Fig. 5 Damping valve device with a solenoid coil

[0019] The Fig. 1 shows a vibration damper 1 in the form of a twin-tube damper with a working cylinder 3, in which an axially movable piston rod 5 with a piston 7 divides the working cylinder 3 into a working chamber 9; 11 on the piston rod side and a working chamber 9; 11 remote from the piston rod. The working chamber 9 on the piston rod side is closed off by a piston rod guide 13. A bottom valve body 15 is arranged on the bottom side, which spatially separates the working chamber 13 remote from the piston rod from a compensation chamber 17. In this exemplary embodiment, the compensation chamber 17 is formed by an inner wall of an outer container tube 19 and an outer wall of the working cylinder 3. The bottom valve body 15 comprises a damping valve acting in the flow direction into the compensation chamber 17 and a check valve opening in the flow direction from the compensation chamber 17 into the working chamber 11 remote from the piston rod.The structural design of these valves is not relevant to the present invention and is therefore not shown.

[0020] The piston 7 fastened to the piston rod 5 has first throttle channels 21 in connection with at least one valve disc 23 for a retraction damping and second throttle channels 25 with at least one valve disc 27 for a pressure damping generated when the piston rod 5 is retracted.

[0021] Within the piston rod side or the piston rod remote or in both working chambers 9; 11, a damping valve device 29 is arranged on the piston rod 5, which in the Fig. 2 is shown enlarged. The damping valve device 29 comprises a throttle point 31 in conjunction with an annular valve element 33 and a flow guide surface 35. The valve element 33 transitions from a flow position to a throttle position depending on the flow velocity of a damping medium within the throttle point 31. It is arranged as a ring element with a variable diameter within an annular groove 37 of a valve carrier 39. The ring element can be designed as a radially elastic ring or as a multi-part ring, optionally slotted via joints. Below a defined flow velocity within the throttle point 31, i.e. below a defined oscillation frequency, only the pressure and / or the pull valve 25; 27 / 21; 23 generate a hydraulic damping force.When excited above the defined oscillation frequency, the flow velocity within the throttle point 31 increases to such an extent that a reduced pressure occurs within the throttle point 31, which acts as a radial force on the valve element 33 in the direction of the flow guide surface 35 of the throttle point 31. The cross-section of the throttle point 31 decreases with increasing flow velocity until it reaches a minimum throttle cross-section, which then generates the maximum damping force relative to the excitation.

[0022] The damping force characteristic of the damping valve device 29 can be actively adjusted by supplying external energy by varying the viscosity of the rheological damping medium located in the working cylinder 3. For this purpose, the vibration damper 1 has a connection lug 40 for a power supply, which is connected to the working cylinder 3 via the electrically conductive piston rod guide 13.

[0023] The piston rod 5 is hollow and therefore offers space for a Fig. 2 symbolically depicts line 41 to valve carrier 39. In this embodiment, a cylinder tube 43 of the working cylinder 3 of the vibration damper 1 is designed as the force field generating element. By applying current to the flow guide surface 35 on the cylinder tube 34 of the rheological medium displaced through the throttle point 31 as the damping medium, a change in the viscosity of the damping medium is induced, thereby increasing the damping force of the vibration damper 1 at a constant excitation.

[0024] In the Fig. 2 shows that the valve element 33 is designed as the second force field generating element. Power is supplied via the hollow piston rod 5 to the valve carrier 39, which comprises two covers 45; 47 forming the annular groove 37, both of which are preferably designed as conductive elements for the force field generating element. In principle, the use of a single cover with a conductive function would also suffice. For this purpose, the entire cover can be made of a material with low conductive resistance, or the cover can have at least one conductive track 49 that establishes the conductive contact with the valve element 33.

[0025] In the execution according to Fig. 3 of the damping valve device 29, the valve carrier 39 is designed as a force field generating element. Thus, the damping valve device 29 comprises two throttle points 31; 51 hydraulically connected in series, wherein the throttle point 31, which has a variable cross-section, is formed by the valve element 33 and the flow guide surface 35, and the second throttle point 51 is formed by an outer circumferential surface 53 of the valve carrier 39, in this case the upper cover 45, and the flow guide surface 35. The field forces are transferred between the cylinder tube 43 and the cover 45. For this purpose, the valve carrier 39 is designed in several parts with at least one inserted insulation element 55; 57, and the valve element 33 functions outside the force field generating element by means of the insulation.

[0026] The design of the damping valve device 29 for a vibration damper 1 requires that the annular groove 37, together with an inner circumferential surface 59 of the valve element 33, form a pressure chamber 61 through which the damping medium flows. The rheological damping medium flows through the pressure chamber 61 via at least one inflow and at least one outflow opening 63; 65. Here, too, the damping force characteristic of the damping valve device 1 can be actively adjusted by supplying external energy, in that the circumferential surface 59 of the valve element 33 and at least portions of the surfaces forming the annular groove 37 of the valve carrier 39 are designed as force field generating elements. An intermediate ring 69 of the valve carrier 39, forming a groove base 67 of the annular groove 37, is designed as a force field generating element.When a voltage is applied between the valve carrier 39 and the valve element 33, the flow through the pressure chamber 61 and thus the radial pressure force on the valve element 33 also changes due to the change in viscosity. The advantage of this solution compared to the design according to the . Fig. 1 to 3 is that the force field generating elements are located within the damping valve device 1, and the cylinder tube 43 is independent of it. Although it still forms the flow guide surface 35, it does not require a power supply.

[0027] The design of the damping valve device 29 according to Fig.5 is based on the same principle, in which the throttle point 31, in conjunction with a valve element 33 and the flow guide surface 35, can be transferred from a flow position into a throttle position depending on the flow velocity of a damping medium within the throttle point 31. Here, too, the valve element 33 is arranged as a ring element with a variable diameter within the annular groove 37 of the valve carrier 39, wherein the damping force characteristic of the damping valve device can be actively adjusted by supplying external energy. In contrast, the damping valve device 29 has a magnetic coil 71 that exerts a radially acting adjusting force on the valve element 33. The magnetic coil 71 is arranged outside the cylinder tube 43, possibly in the compensation chamber 17, parallel to the flow guide surface 35.The valve element 33 is designed to be magnetically conductive, so that when a magnetic field is applied from the solenoid coil 71, an additional radial force acts on the valve element 33. Thus, the magnetic force, relative to a defined excitation of the vibration damper 1, increases the damping force, since the magnetic force tends to act on the valve element 33 in the direction of the flow guide surface 35 and thus toward a maximum throttle position. In this variant, a conventional damping medium can be used. Reference symbol 1 vibration damper 3 working cylinders 5 Piston rod 7 pistons 9 piston rod side working space 11 Working space remote from the piston rod 13 Piston rod guide 15 bottom valve body 17 Compensation room 19 Container pipe 21 first throttle channel 23 Valve disc 25 second throttle channel 27 Valve disc 29 Damping valve device 31 throttle point 33 Valve element 35 Flow guide surface 37 Ring groove 39 valve carriers 40 connection tab 41 Line 43 Cylinder barrel 45 lids 47 lids 49 Conductor track 51 second throttle point 53 lateral surface 55 Insulation element 57 Insulation element 59 Shell surface of the valve element 61 Printing room 63 Inlet opening 65 Outlet opening 67 groove base 69 intermediate ring 71 Solenoid coil QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2016 210 790 A1

[0002] DE 10 2019 212 966 A1

[0004] DE 10 2022 204 988 A1

[0005]

Claims

[1] Damping valve device (29) for a vibration damper (1), comprising a throttle point (31) in conjunction with a valve element (33) and a flow guide surface, wherein the valve element (33) can be transferred from a passage position into a throttle position depending on the flow velocity of a damping medium within the throttle point (31), wherein the valve element (33) is arranged as a ring element whose diameter can be changed within an annular groove (37) of a valve carrier (39), wherein the damping force characteristic of the damping valve device can be actively adjusted by supplying external energy, characterized by that the damping medium displaced by the throttle point (31) is designed as a rheological medium and the flow guide surface (35) is designed as a force field generating element for a viscosity change of the damping medium. [2] Damping valve device (29) according to claim 1, characterized bythat a cylinder tube (43) of a working cylinder (3) of the vibration damper (1) is designed as the force field generating element. [3] Damping valve device (29) according to claim 1 or 2, characterized by that the valve element (33) is designed as the force field generating element. [4] Damping valve device (29) according to at least one of claims 1 to 3, characterized by that the valve carrier (39) comprises two covers (45; 47) forming the annular groove (37), both of which are designed as conductive elements for the force field force generation. [5] Damping valve device (29) according to at least one of claims 1 to 4, characterized by that the valve carrier (39) is designed as a force field generating element. [6] Damping valve device (29) according to at least one of claims 1 to 5, characterized by that the valve carrier (39) is designed in several parts with at least one inserted insulation element (55; 57). [7] Damping valve device (29) according to claim 6, characterized by that the valve element (33) functions outside the force field by means of insulation (55; 57). [8] Damping valve device (29) for a vibration damper (1), comprising a throttle point (31) in conjunction with a valve element (33) and a flow guide surface, wherein the valve element (33) can be transferred from a passage position into a throttle position depending on the flow velocity of a damping medium within the throttle point (31), wherein the valve element (33) is arranged as a ring element whose diameter can be changed within an annular groove (37) of a valve carrier (39), and the annular groove (37) together with a lateral surface (59) of the valve element (33) form a pressure chamber (61) through which the damping medium flows, wherein the damping force characteristic of the damping valve device can be actively adjusted by supplying external energy, characterized bythat the outer surface (59) of the valve element (33) and at least portions of the surfaces forming the annular groove (37) of the valve carrier (39) are designed as field generating elements. [9] Damping valve device (29) according to claim 8, characterized by that an intermediate ring (69) of the valve carrier (39) forming a groove base (67) of the annular groove (37) is designed as a force field generating element. [10] Damping valve device (29) for a vibration damper (1), comprising a throttle point (31) in conjunction with a valve element (33) and a flow guide surface, wherein the valve element (33) can be transferred from a passage position into a throttle position depending on the flow velocity of a damping medium within the throttle point (31), wherein the valve element (33) is arranged as a ring element with a variable diameter within an annular groove (37) of a valve carrier (39), wherein the damping force characteristic of the damping valve device (29) can be actively adjusted by supplying external energy, characterized by that the damping valve device (29) has a magnetic coil (71) which exerts a radially acting adjusting force on the valve element (33).

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